Lovins worked professionally as an environmentalist in the 1970s and since then as an analyst of a "soft energy path" for the United States and other nations. He has promoted energy efficiency, the use of renewable energy sources, and the generation of energy at or near the site where the energy is actually used. Lovins has also promoted a "negawatt revolution" arguing that utility customers do not want kilowatt-hours of electricity; they want energy services. In the 1990s, his work with Rocky Mountain Institute included the design of an ultra-efficient automobile, the Hypercar.